QC/QA is the combination of quality assurance, the process or set of processes used to measure and assure the quality of a product, and quality control, the process of ensuring products and services meet consumer expectations.

Quality assurance is process oriented and focuses on defect prevention, while quality control is product oriented and focuses on defect identification

Quality assurance (QA) is a way of preventing mistakes and defects in manufactured products and avoiding problems when delivering products or services to customers, which ISO 9000 defines as “part of quality management focused on providing confidence that quality requirements will be fulfilled”. This defect prevention in quality assurance differs subtly from defect detection and rejection in quality control

Quality control (QC) is a process by which entities review the quality of all factors involved in production. ISO 9000 defines quality control as “A part of quality management focused on fulfilling quality requirements”.

i) Elements such as controls, job management, defined and well managed processes, performance and integrity criteria, and identification of records.
ii) Competence, such as knowledge, skills, experience, and qualifications.
iii) Soft elements, such as personnel, integrity, confidence, organizational culture, motivation, team spirit, and quality relationships.